Raises an exception.
- iOS 5.0+
- macOS 10.7+
- UIKit for Mac 13.0+Beta
- tvOS 9.0+
- watchOS 2.0+
The object to remove as an observer.
A key-path, relative to the set, for which
observeris registered to receive KVO change notifications. This value must not be
Arbitrary data that is passed to
Value(for Key Path: of: change: context:)
NSSet objects are not observable, so this method raises an exception when invoked on an
NSSet object. Instead of observing a set, observe the unordered to-many relationship for which the set is the collection of related objects.